Various crankshaft piston interface designs are used to improve overall energy efficiency of an internal combustion engine.
U.S. Pat. No. 4,567,866, issued on Feb. 4, 1986 to Applicant, hereby incorporated by reference and claimed any priority thereof, discloses a crankshaft piston interface using a piston-crankshaft linking member and a sliding guide for mounting the fulcrum of the linking member. The design permitted an extended power stroke to more than 180 degrees of rotation of the crankshaft, wherein the piston reaches its top dead center position (“TDC”) at some time after the crank pin and the sliding guide have reached their TDC. The speed at which the piston moves during the following stroke toward its bottom dead center (“BDC”) is lower than the speed of the sliding guide. The piston reaches its BDC after the crankshaft has passed through the 180 degree position, at a time the sliding guide is already moving away from its BDC toward its TDC. Hence, the power stroke and intake stroke extend more than 180 degrees of rotation of the crankshaft. During the compression stroke, the piston moves toward its TDC with a velocity which is higher than that of the sliding guide. While the piston moves from BDC to TDC, the crankshaft rotates less than 180 degrees. Therefore, it is disclosed that the extended power stroke results in higher output of the engine.
The designed engine directly addresses the challenge of heat loss present in all internal combustion engines presently used. It raises the mean effective pressure without raising the compression pressure or changing the cylinder size. Prior art systems extract more power by raising the compression pressure, simply incorporating a super charger, or a turbo charger as it is commonly known as, which causes more air to be pressed into the cylinder, or just increasing the engine size. However, this requires equalizing the mixture of fuel and air, wherein optimal functioning requires an air fuel ratio of 14:1, i.e. 14 pounds of air and 1 pound of fuel. Thus raising the compression pressure requires greater quantities of air to be pressed into the cylinder, thereby using more fuel. Embodiments disclosed enable an increase in the mean effective pressure without altering the air to fuel ratio.
However, this original design is flawed for several reasons. First, on the actual working engine, the pin connecting the main rod of the crankshaft to the sliding guide had to be offset, which caused the sliding guide to be out of balance each time it moved through a full cycle of all four strokes. This resulted in increased stress on the cylinder. The design did not result in a durable, long-lasting crankshaft piston interface. Second, on the original design, the sliding guide used up too much space in the cylinder.